A263795 Number of (n+1)X(4+1) 0..1 arrays with each row and column divisible by 3, read as a binary number with top and left being the most significant bits, and rows and columns lexicographically nonincreasing

3, 3, 7, 7, 17, 18, 56, 66, 218, 272, 798, 1008, 2567, 3227, 7290, 9072, 18622, 22912, 43560, 52998, 94678, 113983, 193427, 230607, 374843, 442911, 694073, 813413, 1235202, 1436754, 2122943, 2452403, 3537837, 4061097, 5735701, 6545785, 9072159

Offset

1,1

Comments

Column 4 of A263799

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = a(n-1) +9*a(n-2) -9*a(n-3) -36*a(n-4) +36*a(n-5) +84*a(n-6) -84*a(n-7) -126*a(n-8) +126*a(n-9) +126*a(n-10) -126*a(n-11) -84*a(n-12) +84*a(n-13) +36*a(n-14) -36*a(n-15) -9*a(n-16) +9*a(n-17) +a(n-18) -a(n-19)

Example

Some solutions for n=5
..1..1..0..0..0....0..0..0..0..0....1..1..1..1..0....1..1..0..0..0
..1..1..0..0..0....0..0..0..0..0....1..1..1..1..0....1..1..0..0..0
..1..1..0..0..0....0..0..0..0..0....1..1..0..0..0....1..1..0..0..0
..1..1..0..0..0....0..0..0..0..0....1..1..0..0..0....1..1..0..0..0
..1..1..0..0..0....0..0..0..0..0....0..0..1..1..0....0..0..0..0..0
..1..1..0..0..0....0..0..0..0..0....0..0..1..1..0....0..0..0..0..0

Crossrefs

Cf. A263799

Sequence in context: A147144 A152113 A146149 * A070925 A146687 A146655

Adjacent sequences: A263792 A263793 A263794 * A263796 A263797 A263798

Keyword

nonn

Author

R. H. Hardin, Oct 26 2015

Status

approved